(CNN) -- Inter Milan's title defense got back on track with a crushing 4-0 win over city rivals AC Milan, after three first-half strikes capitalized on the sending off of Rossoneri skipper Gennaro Gattuso on Saturday night at the San Siro.

Thiago Motta put Jose Mourinho's men in the lead, scoring his first goal for the club after thirty minutes with a left-foot strike, after being played in by fellow new recruit Samuel Eto'o.

The Cameroon striker was involved again for the second when he was fouled when through on goal by an injury-hampered Gattuso to win a penalty for his side, before Diego Milito slotted home from the spot on 36 minutes.

Worse followed for Gattuso when the midfielder received a red card for a tough tackle on Inter debutante Wesley Sneijder, before Brazil full back Maicon took advantage of his opponent's reduced numbers by shooting home form the edge of the area seconds before half time.

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Further humiliation came in the second half for the nominal home side when Serbian Dejan Stankovic crashed home a 30-yard drive to leave Marco Storari to pick the ball form his net for the fourth time that evening with 23 minutes of the game left.

It was a miserable first derby for AC Milan coach Leonardo, who is in the process of rebuilding his side after the departure of former world footballer of the year Kaka to Spanish giants Real Madrid.

Where the Rossoneri have lost talent to Spain, Inter have gained; with former Iberian charges Sneijder and Eto'o contributing well to their side's win.

Holland midfielder Sneijder tested goalkeeper Storari after only six minutes to signal his team's intent while Eto'o had a key role in the following two goals.

Eto'o also had a goal disallowed as he headed into the net from an offside position to cap a telling performance that was in stark contrast to that of Holland international Klass-Jan Huntelaar who made an inauspicious debut for Milan after leaving Real Madrid.

Sully Muntari came on as a second-half substitute, seemingly confirming Mourinho's belief that the player had reduced energy levels as a result of fasting for Ramadan.

Elsewhere in Serie A, Bari drew 0-0 with Bologna despite substitute Ferdinando Sforzini being sent off for the home side as the game drew to a close.

In a game of few chances Daniele De Vezze went closest to opening the scoring for the hosts.